Shears for cutting profiled material



March 24,- 1931. v H. PELS 7 ,7

' SHEARS FOR CUTTING PROFILED MATERIAL Filed Jan 51, 1929 jizz/enforjeizigrek A Morn where the material offers greater resistance PatentedMar. 24, 1931 i UNITED STATES: PATENT OFFICE HENRY PELS, OFIBERLIN-GHABLOTTENBUBG, GERMANY sums 1-03 currme rnorILEn, murmur. IApplication Med January 81, 1929, Serial No. 388,447, anrlln GermanyOctob er 13, 1928.

This invention relates to shears for cutting blank between the same infront elevation rod-shaped material of any profile, especialprior to thecutting. Y ly iron, steel and other metals. Fig. 2 is a verticallongitudinal section on The chief object of the invention is to prolineA-B of Fig. 1. i vide shears of the character just referred to Fig. 3 isa top plan view of the cutting 55 with blades having cutting edges whichwill blades and shows the conformation of their cut material morerapidly and efiiciently than cutting edges. has heretoforebeen possibleand produce In all figures a designates the blank to be smooth faces onthe severed ends" of the matecut, I) designates the upper blade, thelower rial. blade; is is the cutting edge of the upper In the pastwhereit was desired that blade b, and It. the cutting edge of the lowersmooth faces should be formed on the line'of' blade 0. p cut, it hasbeen customary to saw the material. The knives or blades b, 0 movetowards each This manner of cutting the material into other and past oneanother in the direction short pieces is expensive and therefore unf thearrow lines in Figs. 1 and 2. .One of economical, as the sawing requirescomparathe tWO blades m g however be i na y tively much ti and the otherblade might be movable. The The use of shears for cuttingprofiled-maline S'S in Figure 2 designates the plane terial has hithertobeen limited because it has 011 which the material is Separated.- 70 notbeen possible, with cutting blades moving rd g to e i vention t istancebepast one another, to form clean cut faces on tween he Cutting edgesla, 70' of the blades 6, the line of cut. Scales are usually formed 6 ata g t-a gl to th ir direction f m Veon the cut faces and the formationof such ment is a all P i t f the c tting dges 70, k scales i gr te i thinverse proportion t proportional to the thickness at these points theresistance of the material to the cutting. f the Cross Seeti0n f thelank 11 and the Th al hi h b t th t i l greater the resistance of theblank the smaller d li thi kl on th tt f as fl the dlstance is betweenthe cutting edges present the serious inconvenience that they of the l ei do not combine with the main mass of the new gt 1 Parts f the cr ssSection of terial when the material is subsequently subthe matellal ofdifferent thicknesses are indijected to heat treatment. Such blankstherecated y the lines 'f and ha and the by become t p tances betweenthe cutting edges of the out- These inconveniences are avoided accordtmgblades 0 correspondingpoints i t th i ti b a i l construe. of the bladesare indicated in Figure 3 as e, 85 tion of the cutting blades of theshears. The 62 and v invention is characterized by such a confor-'Accordmg to the mventlon the cutting mation of the cutting edges of thecutting edges of the blades. 6 and 0 F ground blades, that the mutualdistance beween the a that the d i' 40 cutting edges parallel to thelongitudinal axis t g g t to t 9 secslon 90 of the blank is varied atall points of the or 93S on t e l h and of v the maternal to be cut, andso that the greater length of the cutting edges in proportlon to thethickness of the be 1 t the thicknessesof the cross. section of the ma agwen v oint the greater the corres ondin distance blank at such P0111tsand at the P 1 hetween the cutting ed es of the bla des b and I 0 willbe. For exam e in the case of a bar smaller than at polnts Where thematervlel of square cross sectior itlie diagonal thickness fers lessreslstance. h is the greatest so that the distance e 'be- The followingfigures of drawings illustween theblades b and 0 at the correspondingtrate the mventlonz parts of said blades is also greatest. At the l Fig.1 shows the cutting blades with the two side corners of the squarecross-section a my hand.

of the blank a the thickness is equal to zero, and the distance betweenthe cutting edges k, k at the corresponding parts of their length mustpractically also be equal to zero. 5 As the thickness of a bar of squarecrosssection decreases from the greatest thickness h towards each sidealong a diagonal line to zero, the distances e between the cutting edges5:, 70 decrease also from the maximum e towards both sides alongstraight lines to zero.

The distance between the cutting edges is and is along their lengthvaries not only according to the variation in thickness of the materialto be cut but also according to the resistance of the material to thecutting. The

. softer the material is, the greater must be the distance between thecutting edges is and is.

A out not only specially clean and smooth but also accurately straight,i. e. perpendicular to the longitudinal axis of the blank, is obtained,when the blank a is inserted between the blades at a slight inclination(Fig. 2).

It is evident, that with shears having cutting blades according to theinvention blanks of a profile composed in any desired manner of straightand curved lines can be cut smooth and straight, rapidly andeconomically.

I claim. 1

Shears for cutting profiled blanks, c0mprising cutting blades movablepast one anotherand of which the distance between the cutting edges in aplane transverse to the blades is greatest at the point of maximumthickness of the material to be cut and decreases towards the points ofminimum thick-- ness of such material proportionately to the decrease ofsuch thickness.

In testimony whereof I have hereunto set HENRY PELS:

